The project uses new methods and sources to measure and interpret the migration behavior of Americans, 1875 to 1915. Migration was critical for industrialization and urbanization at this time, and affected the social adjustment of individuals. Demographers, forced to use crude aggregate data, are now forced to base their theories of individual migratory behavior on European historical data. Historians analyzing social structure by following individuals through their life cycle lost the 50-75% of the population which migrated each decade. This project samples several thousand families from the richest state and special federal censuses from 1875 to 1915 (New York, New Jersey, Wisconsin, Florida, Colorado, Nebraska). Using the recently opened Soundex Index of the Federal Censuses of 1880 and 1900, these families will be traced to wherever in the country they moved. Multivariate analysis will relate the propensity to move, and the distance and direction of movement, to personal, family and community characteristics, and show how the population came to concentrate in urban areas and industrial occupations. This will be the first study of individual movement before the 1930's, and will also provide richly detailed profiles of the population of these representative states. The tracing technique to be developed will find wide application in historical research on demography, social change, population genetics, economic growth, and geographical movement. Data files created will be available to all scholars for research and teaching.